There are many sensors made on textile to detect signals from human or animals. These sensors need to be connected to transmission wires and signal processors for further analysis, especially pressure sensors and strain gauges. There are many types of pressure sensors and strain gauges. For example, PCT/CN2005/001520 discloses an electronic device having a sensor array for detecting pressure points. However, each sensor in the array is identical. Therefore, each sensor has to be connected to the signal processor via its own transmission wires in order for the signal processor to distinguish individual pressure points. It is the same situation in PCT/CN2008/001570, which discloses clothing materials having separate inductive areas, and PCT/CN2008/001571, which discloses clothing materials for forming electronic components.
FIG. 1 shows a side view schematic diagram of a prior art sensing apparatus. The sensing apparatus has three pressure sensors A, B, and C on textile (clothing material) connected to processor 002 in parallel. Sensor A has two output terminals 1 and 2. Terminal 2 is connected to sensing area “111a”, and terminal 1 is connected to sensing area “122a”. Sensor B has output terminals 3 and 4. Terminal 4 is connected to “111b” and terminal 3 is connected to “122b”. Sensor C has output terminals 5 and 6. Terminal 6 is connected to “111c” and terminal 5 is connected to “122c”. The sensors A, B, and C connect with the signal processor 002 via four connection points. One of the connection points is common to output terminals 1, 3, and 5. The other three connection points are separately connected to output terminals 2, 4, and 6. While not pressed, the sensors A, B, and C are in open-circuit state such that the impedance between the terminals is very high. When appropriate force is applied, these sensors are in close-circuit state and the impedance is approximately zero. With such prior art sensing apparatus, when user presses any sensor, the processor 002 would sense the signal. However, in such a sensing apparatus, the signal processor has four connecting points connecting with four terminals from three sensors. That is, there are four independent signal transmission wires disposed on clothing materials, increasing the costs of such materials. It is complicated to arrange output wires on a cloth material, because unlike a circuit board, one cannot implement multi-layer circuits on a cloth or a leather material. In addition, more wires on a cloth material increase the chance of malfunction. After washing, if one of the wires breaks, the sensing apparatus would not work. Furthermore, it is not easy to maintain isolation between the wires. Such materials are not environmental friendly and are prone to short circuits and broken circuits.
The values sensed by pressure sensor A can be adjusted by changing the structure, thickness, or materials in the upper sensing area 111 to produce different pressure responses. For example, the materials can be cotton, nylon, latex rubber, silicone rubber, synthesized sponge, etc. The materials of the sensing area 111a or 122b can be conductive materials such as steel fiber, steel wire, silver fiber, silver wire, conductive rubber, copper fiber, nickel fiber, gold wire, graphite fiber, or conductive plastics.
Referring to FIG. 2, which shows a schematic diagram of a prior art sensing apparatus applied on bed sheet or cushion. Fifteen pressure sensors are fixed on bed sheet to measure posture changes during sleep, e.g., supine, lateral, prone, spasm or no movements. The sensing apparatus can also detect breathing and the time the sleeper lies on bed and gets up. This apparatus has sixteen transmission wires to connect to the input terminals of the signal processor 002. This is tedious to manufacture.
Referring to FIG. 3, which shows another schematic diagram of a prior art sensing apparatus. The bed sheet has three independent signal transmission wires arranged in the X axis and five independent signal transmission wires arranged in the Y axis. The processor 002 connects with eight signal transmission wires. The circuit is complicated and the signal processor 002 cannot get all 15 point signals simultaneously.
Referring to FIG. 4, which shows a schematic diagram of a prior art sensing apparatus. The garment has eight joints (moving locations) on both elbows, shoulders, knees, and hips. There are nine signal transmission wires to connect with the input terminals of the signal processor 002. The lay out design of the wires on the garment is complicated. Its cost is high. With more wires on a garment, there are more chance for wire breakage and it is more difficult to isolate these wires. The materials are not environmental friendly, and they are prone to short circuits or broken circuits.
Referring to FIG. 19, which shows a schematic diagram of a prior art sensing apparatus applied on belt. This belt can detect breathing. Five strain gauges with different tension thresholds (100g, 150g, 200g, 250g, and 300g force thresholds) need six output terminals to connect to the input terminals on the signal processor 002.
In addition, related prior art includes the following:
1. U.S. Pat. No. 6,826,968 discloses cloth materials having sensing devices that use variations of capacitances to detect pressure. As discussed above, assuming N wires in the X axis and M wires in the Y axis, it would need N plus M terminals to connect to the input terminals of a signal processor, which is inconvenient.
2. U.S. Pat. No. 6,210,771 discloses cloth materials having circuit wires running in two orthogonal directions. The circuit wires crisscross; it is difficult to implement. If there is any problem, it would be difficult to determine which element is at fault. More conductive wires on a cloth would make it heavier, and would also make it more likely to fail based on statistics.
3. U.S. Pat. No. 6,729,025 discloses an electrical circuit system fixed on a fabric article, as illustrated in the description. To fix a circuit onto a fabric article, such is garment is complicated and it increases the weight and thickness of the garment. It is not ergonomic, nor is it environment friendly.
4. The membrane switch disclosed in U.S. Pat. No. 6,600,120 is similar to the prior art shown above. Because the upper and low conductors are the same, it needs multiple terminals to connect with processor 002.
5. The textile switching device disclosed in U.S. Pat. No. 7,145,432 also needs multiple output transmission wires, which make it complicated.
6. U.S. Pat. No. 6,642,467 discloses an electrical switch, in which the upper and lower conductors are only textile switch or pressure sensor, and it needs three components.
7. U.S. Pat. No. 6,714,117 discloses a position sensor, which is comprised of two conductive layers and a mid layer in between to detect the signal variations caused by applied force. It is very complicated.
8. U.S. Pat. No. 6,493,933 discloses a textile circuit, in which each electronic component has its own transmission line. Furthermore, components such as processors, IC, Bluetooth, batteries are not water-proof or washable and they produce electromagnetic waves.
9. U.S. Pat. No. 6,809,662 discloses a system with multiple pressure sensors in which conductors are coated on both sides of a polymer film as electrodes. However, transducers are needed to detect the variations of capacitance or resistance at the pressed positions. If one part of the film is broken, the whole system would fail.
The above-mentioned prior art designs need more steps during operations. For example, the user has to connect four sets of terminals if the sensing apparatus has four outputs to signal processor. The designs in these prior patents involve complicated components or too many wires. They are not washable or too difficult to manufacture. It is also difficult to repair once it fails, because it is difficult to find out the locations and the reasons.
Thus, it can be seen that there still exist inconvenience and shortcomings in the structures and applications of current sensors wirings. These would need further improvements. To overcome the problems associated with sensor apparatus wirings, manufacturers are eagerly looking for solutions. However, it has been some time and no suitable designs have been developed. The products available out there do not have the proper structures for solving these problems. This is apparently an urgent problem to be solved in this field. Therefore, how to develop a novel sensing apparatus that is low cost, easy to operate and manufacture, is an important topic for the research and development, and an important goal of the industry.